U.S. patent application number 14/777250 was filed with the patent office on 2016-01-28 for torque transmission device, actuator and robot.
The applicant listed for this patent is SIEMENS AKTIENGESELLSCHAFT. Invention is credited to Georg Bachmaier, Marco Cyriacks, Andreas Godecke, Wolfgang Zols.
Application Number | 20160025150 14/777250 |
Document ID | / |
Family ID | 49998256 |
Filed Date | 2016-01-28 |
United States Patent
Application |
20160025150 |
Kind Code |
A1 |
Bachmaier; Georg ; et
al. |
January 28, 2016 |
TORQUE TRANSMISSION DEVICE, ACTUATOR AND ROBOT
Abstract
The invention relates to a torque transmission device (3), the
stiffness of which can be variably adjusted, to an actuator (1)
having such a torque transmission device (3), and to a robot (26).
The torque transmission device (3) according to the invention has
an inner ring (5), an outer ring (4) that is arranged as to be
rotatable to the inner ring (5) from a neutral position (25) in a
positive rotational direction (17) or a negative rotational
direction (18) to the inner ring, at least one pair of receiving
bellows (9, 10), comprising a positive receiving bellows (9) and a
negative receiving bellows (10), at least one gas pressure spring
(13), and an adjusting unit connected to the at least one gas
pressure spring (13). The receiving bellows (9, 10) are arranged
between the outer ring (4) and the inner ring (5) in such a way
that when the inner ring (5) is rotated in the positive rotational
direction (17), the positive receiving bellows (9) can be
compressed, and when the inner ring (5) is rotated in the negative
rotational direction (18), the negative receiving bellows (10) can
be compressed. In addition, the receiving bellows (9, 10) are
connected to the at least one gas pressure spring (13) in a
fluidically conductive manner.
Inventors: |
Bachmaier; Georg; (Munchen,
DE) ; Cyriacks; Marco; (Munchen, DE) ;
Godecke; Andreas; (Munchen, DE) ; Zols; Wolfgang;
(Munchen-Lochhausen, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SIEMENS AKTIENGESELLSCHAFT |
Munchen |
|
DE |
|
|
Family ID: |
49998256 |
Appl. No.: |
14/777250 |
Filed: |
January 15, 2014 |
PCT Filed: |
January 15, 2014 |
PCT NO: |
PCT/EP2014/050710 |
371 Date: |
September 15, 2015 |
Current U.S.
Class: |
464/28 ; 901/19;
901/23 |
Current CPC
Class: |
F16D 3/80 20130101; B25J
9/126 20130101; Y10S 901/23 20130101; F16D 3/66 20130101; F16F
15/161 20130101; F16F 15/023 20130101; Y10S 901/19 20130101 |
International
Class: |
F16D 3/80 20060101
F16D003/80; B25J 9/12 20060101 B25J009/12; F16D 3/66 20060101
F16D003/66 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 15, 2013 |
DE |
10 2013 204 588.3 |
Claims
1. A torque transmission device comprising: an inner ring; an outer
ring arranged so as to be rotatable relative to the inner ring from
a neutral position in a positive direction of rotation or negative
direction of rotation; at least one pair of receiving bellows
comprising a positive receiving bellows and a negative receiving
bellows; at least one gas pressure spring; and an adjusting unit
connected to the at least one gas pressure spring, wherein the
receiving bellows are arranged between the outer ring and the inner
ring in such a manner that the positive receiving bellows is
compressible when the inner ring is rotated in the positive
direction of rotation and the negative receiving bellows is
compressible when the inner ring is rotated in the negative
direction of rotation, and wherein the receiving bellows are
connected to the at least one gas pressure spring so as to conduct
fluid.
2. The torque transmission device as claimed in claim 1, wherein
the at least one gas pressure spring comprises a hermetically
sealed gas pressure chamber and a transmission bellows that
projects into the gas pressure chamber and an adjusting bellows
that projects into the gas pressure chamber, wherein the receiving
bellows are connected to the transmission bellows so as to conduct
fluid and the adjusting unit is connected to the adjusting bellows
so as to conduct fluid.
3. The torque transmission device as claimed in claim 2, wherein
the adjusting unit includes comprises a reservoir and a pump.
4. The torque transmission device as claimed in claim 3, wherein
the pump is a piezo-pump.
5. The torque transmission device as claimed in claim 1, wherein
the torque transmission device comprises two gas pressure springs
connected to the adjusting unit, wherein the at least one positive
receiving bellows is connected to one of the two gas pressure
springs so as to conduct fluid and the at least one negative
receiving bellows is connected to the other of the two gas pressure
springs so as to conduct fluid.
6. The torque transmission device as claimed in claim 5, wherein
the adjusting unit comprises a separate pump per gas pressure
spring.
7. The torque transmission device as claimed in claim 1, wherein
the at least one pair of receiving bellows comprises two pairs of
receiving bellows.
8. The torque transmission device as claimed in claim 1, wherein
the torque transmission device comprises a form of a cylinder with
a circular surface area.
9. The torque transmission device as claimed in claim 1, wherein at
least one bellows of the at least one pair of bellows is a metal
bellows.
10. An actuator comprising: a torque transmission device
comprising: an inner ring; an outer ring arranged so as to be
rotatable relative to the inner ring from a neutral position in a
positive direction of rotation or negative direction of rotation;
at least one pair of receiving bellows comprising a positive
receiving bellows and a negative receiving bellows; at least one
gas pressure spring; and an adjusting unit connected to the at
least one gas pressure spring, wherein the receiving bellows are
arranged between the outer ring and the inner ring in such a manner
that the positive receiving bellows is compressible when the inner
ring is rotated in the positive direction of rotation and the
negative receiving bellows is compressible when the inner ring is
rotated in the negative direction of rotation, and wherein the
receiving bellows are connected to the at least one gas pressure
spring so as to conduct fluid; and a servomotor comprising: a
rotor; and a stator, wherein the stator is non-rotatably connected
to the outer ring or the inner ring of the torque transmission
device.
11. A robot comprising: a mechanical unit; and an actuator
comprising: a torque transmission device comprising: an inner ring;
an outer ring arranged so as to be rotatable relative to the inner
ring from a neutral position in a positive direction of rotation or
negative direction of rotation; at least one pair of receiving
bellows comprising a positive receiving bellows and a negative
receiving bellows; at least one gas pressure spring; and an
adjusting unit connected to the at least one gas pressure spring,
wherein the receiving bellows are arranged between the outer ring
and the inner ring in such a manner that the positive receiving
bellows is compressible when the inner ring is rotated in the
positive direction of rotation and the negative receiving bellows
is compressible when the inner ring is rotated in the negative
direction of rotation, and wherein the receiving bellows are
connected to the at least one gas pressure spring so as to conduct
fluid; a servomotor comprising: a rotor; and a stator, wherein the
stator is non-rotatably connected to the outer ring or the inner
ring of the torque transmission device, wherein the actuator is
connected to the mechanical unit so as to transmit force or so as
to transmit torque.
12. The torque transmission device as claimed in claim 4, wherein
the torque transmission device comprises two gas pressure springs
connected to the adjusting unit, wherein the at least one positive
receiving bellows is connected to one of the two gas pressure
springs so as to conduct fluid and the at least one negative
receiving bellows is connected to the other of the two gas pressure
springs so as to conduct fluid.
13. The torque transmission device as claimed in claim 12, wherein
the at least one pair of receiving bellows comprises two pairs of
receiving bellows.
14. The torque transmission device as claimed in claim 13, wherein
the torque transmission device comprises a form of a cylinder with
a circular surface area.
15. The torque transmission device as claimed in claim 14, wherein
at least one bellows of the at least one pair of bellows is a metal
bellows.
16. The torque transmission device as claimed in claim 5, wherein
the at least one pair of receiving bellows comprises two pairs of
receiving bellows.
17. The torque transmission device as claimed in claim 5, wherein
the torque transmission device comprises a form of a cylinder with
a circular surface area.
18. The torque transmission device as claimed in claim 5, wherein
at least one bellows of the at least one pair of bellows is a metal
bellows.
Description
[0001] The present invention relates to a torque transmission
device having variably adjustable stiffness, to an actuator having
said torque transmission device and to a robot.
[0002] Robots are being used more and more in direct contact with
humans whether in patient care or in industry. Common to these
applications is that an increased demand is made on the safety of
robots. Thus, a human being injured by a robot if he is
accidentally struck by a moving robot part has to be ruled out. In
the event of faults, above all in the area of wearable robotics, a
human joint being acted upon with too much force and as a result
being injured also has to be ruled out. A known approach to this
problem is the use of actuators with variable stiffness.
[0003] A high degree of mechanical stiffness is desired for
achieving high levels of positioning accuracy. However, if a robot
part is to be moved rapidly, or if the movement of a human joint is
to be matched, a flexible mechanism and consequently a low degree
of stiffness is desirable for achieving a high level of safety. Two
approaches are known for realizing actuators with variable
stiffness (VSA in short for variable stiffness actuator).
[0004] On the one hand, actuators with a high degree of stiffness
are supplemented by a force or torque sensor. By means of a
suitable controller, this makes it possible to simulate a stiffness
which is below the mechanical one. The force sensor, in this case,
measures the force existing at the actuator or the existing torque.
In dependence on the torque, the excursion is adjusted such that a
mechanical spring is simulated.
[0005] The excursion is adjusted in proportion to the existing
torque, the proportionality factor corresponding to the virtual
stiffness. A disadvantage of the approach is the lack of intrinsic
safety as in the event of a fault, for example failure of the force
sensor or the control means, the intrinsic high degree of stiffness
of the actuator comes into play.
[0006] The second approach is the structure of actuators, the
stiffness of which is realized so as to be modifiable in a purely
mechanical manner. In this case, lever system with a variable force
application are used. An actuator is connected for this purpose,
for example by means of an additional mechanical element which
includes a spring as a central mechanism. In order to vary the
stiffness of the spring, the lever arm of the force application is
adjustable, for example, by means of an electric motor. A
disadvantage of said approach is the relatively large amount of
space required for the structure.
[0007] The object underlying the present invention is to eliminate
said disadvantages and to provide an improved actuator with
variable stiffness.
[0008] Said object is achieved with a torque transmission device
according to claim 1, an actuator according to claim 10 and a robot
according to claim 11. Advantageous further developments of the
invention are described in the sub-claims and in the
description.
[0009] The torque transmission device according to the invention is
provided with an inner ring, an outer ring which is arranged so as
to be rotatable relative to the inner ring from a neutral position
in a positive direction of rotation or negative direction of
rotation, at least one pair of receiving bellows, including a
positive receiving bellows and a negative receiving bellows, at
least one gas pressure spring and an adjusting unit which is
connected to the at least one gas pressure spring. The receiving
bellows are arranged between the outer ring and the inner ring in
such a manner that the positive receiving bellows is compressible
when the inner ring is rotated in the positive direction of
rotation and the negative receiving bellows is compressible when
the inner ring is rotated in the negative direction of rotation.
The receiving bellows are additionally connected to the at least
one gas pressure spring so as to conduct fluid. In a preferred
manner, in this case, a hydraulic fluid is used as fluid.
[0010] In an advantageous manner, the torque transmission device
according to the invention comprises very compact dimensions and,
with the almost incompressible hydraulic fluid, is capable of
providing very high degrees of stiffness. The hydraulic force
transmission also comprises a high level of self-damping, the
natural vibrations of the system are strongly over-damped and only
appear in the event of high frequencies. Consequently the frequency
response of the system is linear up to high frequencies, which
means the torque transmission device according to the invention has
good controllability.
[0011] In an advantageous development of the torque transmission
device according to the invention, the at least one gas pressure
spring comprises a hermetically sealed gas pressure chamber and a
transmission bellows which projects into the gas pressure chamber
and an adjusting bellows which projects into the gas pressure
chamber. The receiving bellows, in this case, are connected to the
transmission bellows so as to conduct fluid and the adjusting unit
is connected to the adjusting bellows so as to conduct fluid.
[0012] An adjustable, compact and more durable gas pressure spring
is realized in this manner.
[0013] In a further advantageous development of the torque
transmission device according to the invention, the adjusting unit
includes a reservoir and a pump. The pump, in this case, is in
particular a piezo-pump. The piezo-pumps can be additionally
provided with a non-return valve which is designed to be
self-opening in the event of a fault (normally open).
[0014] With the reservoir and the pump, a hydraulic adjusting unit
with simple and cost-efficient components is provided. In an
advantageous manner, the piezo-pump requires a small installation
space and operates in an effective manner. In the event of a fault,
for example if the power supply or the control signal fails, the
stiffness of the transmission torque device is automatically
reduced to the minimum by way of the non-return valve, which
provides the safe state of the system: the system is consequently
intrinsically safe.
[0015] In a further advantageous development of the torque
transmission device according to the invention, the torque
transmission device comprises two gas pressure springs which are
connected to the adjusting unit. In this case, the at least one
positive receiving bellows is connected to one of the two gas
pressure springs so as to conduct fluid and the at least one
negative receiving bellows is connected to the other of the two gas
pressure springs so as to conduct fluid.
[0016] Consequently, the receiving bellows have one gas pressure
spring available in each case both for the compression movement and
for the expansion movement. In an advantageous manner, both
compression phases and tension phases of the receiving bellows are
able to be influenced.
[0017] In a further advantageous development of the torque
transmission device according to the invention, the adjusting unit
includes a separate pump per gas pressure spring.
[0018] The gas pressure springs can consequently be adjusted
independently of one another. In an advantageous manner, the
stiffness of the torque transmission device is consequently
designable and modifiable in a different manner in dependence on
the direction. The compression phases are able to be designed
differently to the tension phases. In a further advantageous
development of the torque transmission device according to the
invention, the torque transmission device includes two pairs of
receiving bellows.
[0019] Consequently, the introduction of force can be distributed
in a better manner. The individual receiving bellows are
consequently exposed to smaller loads. In addition, the guiding of
the inner ring is improved without additional supporting
elements.
[0020] In a further advantageous development of the torque
transmission device according to the invention, at least one of the
bellows is a metal bellows.
[0021] Metal bellows are extremely sturdy, even at high
temperatures and under the influence of aggressive environmental
conditions. This lends durability and safety to the torque
transmission device.
[0022] In a further advantageous development of the torque
transmission device according to the invention, the torque
transmission device comprises substantially the form of a cylinder
with a circular surface area.
[0023] Consequently, the torque transmission device is provided
with a shape which can easily be added to the shape of a usual
servomotor. The servomotor and the torque transmission device
together only take up a little more space than the servomotor on
its own.
[0024] Thus, in a preferred manner, the torque transmission device
according to the invention is integrated in all its developments
into an actuator which comprises a servomotor along with the torque
transmission device. The servomotor includes a rotor and a stator.
According to the invention, the stator of the servomotor is
non-rotatably connected to the outer ring or the inner ring of the
torque transmission device.
[0025] Consequently, an actuator with variable stiffness is
provided in an advantageous manner. The advantages of the torque
transmission device according to the invention are seen with the
actuator as a module. In a preferred manner, the actuator according
to the invention is integrated in a robot. The actuator, in this
case, is connected to the mechanical unit so as to transmit force
or so as to transmit torque.
[0026] The mechanical unit of the robot can be operated with
different levels of stiffness on account of the actuator according
to the invention. Consequently, the robot provides a high level of
safety precisely in direct contact with humans.
[0027] Exemplary embodiments of the invention are explained in more
detail by way of drawings and the following description, in
which:
[0028] FIG. 1 shows a robot according to the invention;
[0029] FIG. 2 shows an actuator according to the invention; and
[0030] FIGS. 3 to 5 show different developments of a torque
transmission device of the actuator according to the invention.
[0031] A sketch of the robot 26 according to the invention is shown
in FIG. 1. The robot 26 according to the invention comprises an
actuator 1 which is connected to a mechanical unit 27 so as to
transmit force or so as to transmit torque. The position of the
mechanical unit 27 is modifiable as a result of the operation of
the actuator 1. The mechanical unit 27 is realized so as to convert
the movement generated by the actuator 1. The mechanical unit 27 is
able to perform, for example, a rotation, a translatory movement or
a combination of both movements.
[0032] A sketch of the actuator 1 according to the invention is
shown as an example in FIG. 2.
[0033] The actuator 1 comprises a servomotor 2 and a torque
transmission device 3. The servomotor 2 includes a rotor 21 and a
stator 22. The rotor 21 is mounted on a rotational axis 23 so as to
rotate in relation to the stator 22. The stator 22 can be arranged
around the rotor 21, it is shown in this manner in FIG. 1. The
rotor 21 can also be arranged around the stator 22. In terms of the
present invention, the stator 22 is the supporting element and the
rotor 21 is the movable element. According to the invention, the
stator 22 is non-rotatably connected to the torque transmission
device 3.
[0034] According to the invention, the torque transmission device 3
includes an inner ring 5 and an outer ring 4 which is arranged
around the inner ring 5. The outer ring 4 and the inner ring 5 are
arranged concentrically with respect to the rotational axis 23. The
outer ring 4 is rotatable about a certain torsional angle on the
rotational axis 23 in relation to the inner ring 5. In the example
shown in FIG. 1, the inner ring 5 of the torque transmission device
3 is fixedly clamped and the stator 22 of the servomotor 2 is
fastened to the outside ring 4 of the torque transmission device 3
so as to transmit torque. Torque reduction 20 can consequently take
place at the rotor 21. It is also possible for the outer ring 4 of
the torque transmission device 3 to be fixedly clamped and the
stator 22 of the servomotor 2 to be non-rotatably connected to the
inner ring 5 of the torque transmission device 3.
[0035] Different realization variants of the torque transmission
device 3 are sketched as an example in FIGS. 2 to 4. In addition to
the outer ring 4 and to the inner ring 5, the torque transmission
device 3 according to the invention includes at least one pair of
receiving bellows 9, 10, a gas pressure spring 13, an adjusting
unit and fluid lines 16.
[0036] In FIGS. 2 to 4, the inner ring 5 of the torque transmission
device 3 according to the invention is shown in each case in a
neutral position. The inner ring 5 is able to rotate in a positive
direction of rotation 17 or in a negative direction of rotation 18
in relation to the outer ring 4.
[0037] The outer ring 4 comprises at least two moldings 24. Each
molding 24 projects into a recess 7 of the inner ring 5. At least
one driver 6 is situated in each case at the moldings 24. At each
recess 7, the inner ring 5 comprises a support 8 at a region that
is positioned opposite the driver 6. In each case one of the
receiving bellows 9, 10 is arranged between the support 8 of the
inner ring 5 and the driver 6 of the outer ring 4. The receiving
bellows 9, 10 are fastened in each case at least to the support 8.
In terms of the present invention, a bellows can also be a
hydraulic cylinder or the like, the bellows is in particular
produced from metal.
[0038] The at least one pair of receiving bellows 9, 10 includes a
positive receiving bellows 9 and a negative receiving bellows 10.
In terms of the present invention, the positive receiving bellows 9
is arranged in such a manner that it is compressed when the inner
ring 5 is modified 5 in the positive direction of rotation 17 from
the neutral position 2. The negative receiving bellows 10 is
arranged according to the invention in such a manner that it is
compressed when the inner ring 5 is modified in the negative
direction of rotation 18 from the neutral position.
[0039] The receiving bellows 9, 10 are provided according to the
invention with a fluid, in particular with a hydraulic fluid, such
as, for example, silicone oil or glycerin. The receiving bellows 9,
10 are connected to the at least one gas pressure spring 13 so as
to conduct fluid by means of the fluid lines 16.
[0040] According to the invention, the at least one gas pressure
spring 13 comprises a hermetically sealed gas pressure chamber 28
which is filled with a fluid. The fluid is in particular a gas and
can be at an overpressure of between 2 bar and 10 bar. Two bellows
14, 15 which are positioned in particular opposite one another, are
arranged projecting into the gas pressure chamber 28--a
transmission bellows 14 and a receiving bellows 15. The
transmission bellows 14 is connected to the adjusting unit so as to
conduct fluid by means of fluid lines 16. The adjusting bellows 15
is connected to the adjusting unit so as to conduct fluid by means
of fluid lines 16.
[0041] According to the invention, the adjusting unit comprises at
least one pump 12, in particular a piezo-pump 12, and a reservoir
11 in which a fluid, in particular a hydraulic fluid, can be
held.
[0042] When the inner ring 5 is rotated in the positive direction
of rotation 17 in relation to the outer ring 4, the pressure in the
positive receiving bellows 9 is increased and a hydraulic fluid
that is situated in the positive receiving bellows 9 is conducted
through the fluid line 16 into the transmission bellows 14 of the
at least one gas pressure spring 13. The transmission bellows 14
attempts to expand. According to the invention, the torque
necessary for rotation in the positive direction of rotation 17 is
adjustable in a variable manner by the pressure in the gas pressure
chamber 28.
[0043] When the inner ring 5 is rotated in the negative direction
of rotation 18 in relation to the outer ring 4, the pressure in the
negative receiving bellows 10 is increased and a hydraulic fluid
located in the negative receiving bellows 10 is conducted through
the fluid line 16 into the transmission bellows 14 of the at least
one gas pressure spring 13. The transmission bellows 14 attempts to
expand. According to the invention, the torque necessary for
rotation in the negative direction of rotation 18 is adjustable in
a variable manner by the pressure in the gas pressure chamber
28.
[0044] The pressure in the gas pressure chamber 28 of the gas
pressure spring 13 acts on the transmission bellows 14 and the
adjusting bellows 15. The adjusting bellow 15 is realized in such a
manner that the gas volume in the gas pressure spring 13 is
compressible. By means of the pump 12 of the adjusting unit, a
fluid, in particular a hydraulic fluid, is pumpable out of the
reservoir 11 into the adjusting bellows 15--or out of the adjusting
bellows 15. In this way, the stiffness of the gas pressure spring
13 is able to be adjusted within a broad range.
[0045] If the adjusting bellows 15 is completely emptied, the gas
in the gas pressure chamber 28 can take-in a high volume at a low
pressure. The transmission bellows 14 can consequently expand
without the pressure in the gas pressure chamber 28 increasing
significantly, i.e. the gas pressure spring 13 has a small amount
of stiffness in this position.
[0046] If the adjusting bellows 15, in contrast, is filled up to
its end position, as is thus shown in FIGS. 3 to 5, a slight
expansion of the transmission bellows 15 already results in a high
increase in pressure in the gas pressure chamber 28 and
consequently in a high counter force onto the transmission bellows.
The gas pressure spring 13 has a high level of stiffness in this
position.
[0047] As the transmission bellows 14 transmits the pressure of the
gas pressure chamber 28 of the gas pressure spring 13 to the
receiving bellows 9, 10, and a torque is built up there, the
variable stiffness of the gas pressure spring 13 therefore
translates directly into a variable torsion spring characteristic.
According to the invention, the volume of the adjusting bellows 15
is variable by means of the pump 12 and as a result the rotational
stiffness of the torque transmission device 3 according to the
invention is adjustable. This is effected within a few seconds or
fractions of a second, depending on the design of the output of the
pump 12.
[0048] The adjusting unit is controlled or regulated by a control
unit which is not shown here in any detail and to which the
adjusting unit is connected. In addition, sensors which detect
states such as, for example, the pressure in at least one of the
bellows, can be arranged in the torque transmission device 3.
[0049] The torque transmission device 3 can also comprise support
elements. For example, rolling elements can be arranged between the
outer ring 4 and the inner ring 5.
[0050] The realization variant of the torque transmission device 3
according to the invention sketched as an example in FIG. 3
comprises one single pair of receiving bellows 9, 10 and one single
gas pressure spring 13. The adjusting unit comprises one single
pump 12.
[0051] The receiving bellows 9, 10 are fastened here in each case
to the support 9 and rest loosely on the driver 6. The receiving
bellows 9, 10 comprise in each case a stop 19 which prevents the
receiving bellows 9, 10 expanding beyond the dimension available
when the inner ring 5 is in the neutral position 25. Both receiving
bellows 9, 10 comprise their maximum volume in the neutral position
25. When the inner ring 5 is rotated in relation to the outer ring
5 out of the neutral position, one of the receiving bellows 9, 10
is compressed, the other of the receiving bellows 10, 9 maintains
its volume. During said compression, the above-described damping is
performed by the gas pressure spring 13. The torque transmission
device 3 has no stiffness when it is rotated in the opposite
direction into the neutral position 25. Torque is able to work
freely until the neutral position has been reached again.
[0052] Compared to the variant shown in FIG. 3, the realization
variant of the torque transmission device 3 according to the
invention sketched as an example in FIG. 4 comprises two gas
pressure springs 13. Each of the gas pressure springs is connected
to one receiving bellows 9, 10 of the pair of receiving bellows,
here just one single pair, by means of fluid lines 16 so as to
conduct fluid.
[0053] With two gas pressure springs 13, the number of gas pressure
springs 13 corresponds to the possible directions of rotation 17,
18. The two gas pressure springs 13 are separately controllable.
The adjusting unit includes two pumps 12 for this purpose.
Consequently, the receiving bellows 9, 10 are able to be influenced
in each case not only in a pressure phase but also in a tension
phase. Whereas one of the gas pressure springs 13 accompanies the
pressure phase of the one receiving bellows 9, 10, at the same time
the other of the gas pressure springs 13 influences the tension
phase of the other receiving bellows 10, 9.
[0054] The receiving bellows 9, 10 do not comprise a stop 19 in
this case. The receiving bellows 9, 10 are fastened in each case
both to the support 8 of the inner ring 5 and to the driver 6 of
the outer ring 4. The positive receiving bellows 9 comprises its
greatest volume with the inner ring 5 in the position in which the
negative receiving bellows 10 comprises its smallest volume and
vice versa. In particular, both pumps 12 can be operated in
parallel in such a manner that the gas pressure springs 13 in each
case comprise the same inner stiffness.
[0055] In addition to the realization variant shown in FIG. 4, the
realization variant of the torque transmission device 3 according
to the invention sketched as an example in FIG. 5 comprises two
pairs of receiving bellows 9, 10. In this case, the two positive
receiving bellows 9 are connected in parallel and the two negative
receiving bellows 10 are connected in parallel.
[0056] Although the invention has been illustrated and described in
detail by the preferred exemplary embodiment, the invention is not
restricted by the disclosed examples and other variations can be
derived herefrom by the person skilled in the art without departing
from the scope of protection of the invention.
* * * * *